1. Field of the Invention
The present invention relates to methods of controlling motors, motor control devices, and printing methods.
2. Description of the Related Art
Printers are provided with various types of motors, including carriage motors for moving a carriage and carry motors for carrying paper. When being driven, such motors generate heat in accordance with their power consumption. When the motor temperature becomes high due to this heat, then this may lead to damage to the motor. Accordingly, it is necessary to monitor the motor temperature.
One way to detect the motor temperature is to detect the motor temperature by providing a temperature sensor. However, this increases the number of parts and therefore leads to higher costs. Then there is the method of estimating the motor temperature based on the value of the current flowing through the motor when the motor is being driven, as disclosed in JP 2003-79178A.
Incidentally, motors used in printers move an object to be moved to a target position by first accelerating the object to be moved and then moving it at a constant velocity. During this period, the current flowing through the motor is not uniform. Therefore, the issue here is how to estimate the motor temperature from such a changing current.
In JP 2003-79178A, the constant current value during the movement at constant velocity is taken to be IFuka, the current value of an inertia component is taken to be Ibase, and the heat generation amount Qpass (=Ipass2×t) is calculated from an effective current value Ipass obtained by adding IFuka and Ibase.
In JP 2003-79178A, current values Ibase of the inertia component are stored in correspondence with the movement distances and the movement velocities of the object to be moved. However, if the range of movement distances or movement velocities of the object to be moved is large, then the amount of data to be stored becomes large.